Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 9 · Vastu, Griha Pravesha
वास्तु गृहप्रवेशश्च
खदिरार्जुनशालोत्थं युगयंत्रं तरूद्भवम् ।रक्तचंदनपालाशरक्तशालविशालजम् ॥ ५७४ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 574.
The peg is made from the wood of a khadira, arjuna or shala tree. Or it is made from red sandalwood, palasha, red shala or vishala wood.
Simple meaning: The peg is made of wood such as khadira, arjuna, shala or red sandalwood.
शंकुं त्रिधा विभज्याद्यं चतुरस्रं ततः परम् ।
Make the peg in three parts: four-sided, eight-sided and 14-sided. It must be smooth and flawless.
एवं लक्षणसंयुक्तं परिकल्प्य शुभे दिने ।
Make the peg on a good day and set it on ground marked out with the thread.
मृदुध्रुवक्षिप्रभेषु रिक्तामावर्जिते दिने ।
Choose a good star and a good weekday, avoid empty days, and keep the 8th house free of bad planets.